Python: started adding some coverage tests

Author: yoff

python/ql/test/experimental/dataflow/coverage/dataflow.expected

@@ -0,0 +1,6 @@
+| test.py:20:9:20:14 | ControlFlowNode for SOURCE | test.py:21:10:21:10 | ControlFlowNode for x |
+| test.py:25:9:25:16 | ControlFlowNode for Str | test.py:26:10:26:10 | ControlFlowNode for x |
+| test.py:29:9:29:17 | ControlFlowNode for Str | test.py:30:10:30:10 | ControlFlowNode for x |
+| test.py:33:9:33:10 | ControlFlowNode for IntegerLiteral | test.py:34:10:34:10 | ControlFlowNode for x |
+| test.py:37:9:37:12 | ControlFlowNode for FloatLiteral | test.py:38:10:38:10 | ControlFlowNode for x |
+| test.py:46:10:46:15 | ControlFlowNode for SOURCE | test.py:47:10:47:10 | ControlFlowNode for x |

python/ql/test/experimental/dataflow/coverage/localFlow.expected

@@ -1,3 +1,5 @@
+| test.py:12:1:12:33 | GSSA Variable SINK | test.py:15:5:15:8 | ControlFlowNode for SINK |
+| test.py:12:1:12:33 | GSSA Variable SOURCE | test.py:13:13:13:18 | ControlFlowNode for SOURCE |
 | test.py:13:5:13:5 | SSA variable x | test.py:12:1:12:33 | Exit node for Function test_tuple_with_local_flow |
 | test.py:13:5:13:5 | SSA variable x | test.py:14:9:14:9 | ControlFlowNode for x |
 | test.py:13:10:13:18 | ControlFlowNode for Tuple | test.py:13:5:13:5 | SSA variable x |

python/ql/test/experimental/dataflow/coverage/test.py

@@ -4,16 +4,91 @@
 #
 # Functions whose name ends with "_with_local_flow" will also be tested for local flow.
 
-# Uncomment these to test the test code
-# SOURCE = 42
-# def SINK(x):
-#     return 42
+# These are included so that we can easily evaluate the test code
+SOURCE = "source"
+def SINK(x):
+    print(x)
 
 def test_tuple_with_local_flow():
     x = (3, SOURCE)
     y = x[1]
     SINK(y)
 
+# List taken from https://docs.python.org/3/reference/expressions.html
+# 6.2.1. Identifiers (Names)
+def test_names():
+    x = SOURCE
+    SINK(x)
+
+# 6.2.2. Literals
+def test_string_literal():
+    x = "source"
+    SINK(x)
+
+def test_bytes_literal():
+    x = b"source"
+    SINK(x)
+
+def test_integer_literal():
+    x = 42
+    SINK(x)
+
+def test_floatnumber_literal():
+    x = 42.0
+    SINK(x)
+
+def test_imagnumber_literal():
+    x = 42j
+    SINK(x)
+
+# 6.2.3. Parenthesized forms
+def test_parenthesized_form():
+    x = (SOURCE)
+    SINK(x)
+
+# 6.2.5. List displays
+def test_list_display():
+    x = [SOURCE]
+    SINK(x[0])
+
+def test_list_comprehension():
+    x = [SOURCE for y in [3]]
+    SINK(x[0])
+
+def test_nested_list_display():
+    x = [* [SOURCE]]
+    SINK(x[0])
+
+# 6.2.6. Set displays
+def test_set_display():
+    x = {SOURCE}
+    SINK(x.pop())
+
+def test_set_comprehension():
+    x = {SOURCE for y in [3]}
+    SINK(x.pop())
+
+def test_nested_set_display():
+    x = {* {SOURCE}}
+    SINK(x.pop())
+
+# 6.2.7. Dictionary displays
+def test_dict_display():
+    x = {"s": SOURCE}
+    SINK(x["s"])
+
+def test_dict_comprehension():
+    x = {y: SOURCE for y in ["s"]}
+    SINK(x["s"])
+
+def test_nested_dict_display():
+    x = {** {"s": SOURCE}}
+    SINK(x["s"])
+
+# 6.2.8. Generator expressions
+def test_generator():
+    x = (SOURCE for y in [3])
+    SINK([*x][0])
 
 # List taken from https://docs.python.org/3/reference/expressions.html
 # 6. Expressions

python/ql/test/experimental/dataflow/regression/test.py

@@ -159,9 +159,9 @@ def test_truth():
     if t:
         SINK(t)
     else:
-        SINK(t)
+        SINK(t) # Regression: FP here
     if not t:
-        SINK(t)
+        SINK(t) # Regression: FP here
     else:
         SINK(t)
 

python/ql/test/experimental/dataflow/testConfig.qll

@@ -9,6 +9,15 @@
  *      SINK(s)
  * ```
  * `SOURCE` will be a source and the second occurance of `s` will be a sink.
+ * 
+ * In order to test literals, alternative sources are defined for each type:
+ * 
+ *  for | use
+ * ----------
+ * string | `"source"`
+ * integer | `42`
+ * float | `42.0`
+ * complex | `42j` (not supported yet)
  */
 
 import experimental.dataflow.DataFlow
@@ -18,6 +27,13 @@ class TestConfiguration extends DataFlow::Configuration {
 
   override predicate isSource(DataFlow::Node node) {
     node.asCfgNode().(NameNode).getId() = "SOURCE"
+    or
+    node.asCfgNode().getNode().(StrConst).getS() = "source"
+    or
+    node.asCfgNode().getNode().(IntegerLiteral).getN() = "42"
+    or
+    node.asCfgNode().getNode().(FloatLiteral).getN() = "42.0"
+    // No support for complex numbers
   }
 
   override predicate isSink(DataFlow::Node node) {